Microencapsulation of polyphenols - The specific case of the microencapsulation of Sambucus Nigra L. extracts - A review

Background: Nowadays, diseases like cancer, Alzheimer and Parkinson are becoming more common, being a result of an uncontrolled production of free radicals and an unbalanced mechanism of antioxidant protection. In this context, antioxidants compounds emerge as effective and continuous prevention agents of the above-mentioned diseases. The most available and soft antioxidant substances are the natural ones, like the polyphenols, that can be found in some everyday foods. However, the consumption of this type of products do not provide the necessary antioxidants amount and, for that reason, the production of functional products, incorporated with natural antioxidant compounds, has become more relevant. Scope and approach: Several limitations have been associated with the use of these substances, due to their high probability of being degraded if exposed to adverse conditions. A viable solution is the use of microencapsulation techniques, which allow the protection of the biochemical functionalities of a wide range of compounds, by their incorporation into a protective matrix. Key findings and conclusions: The main purpose of the current work is to focus on important topics about the microencapsulation of polyphenols, studying the specific case of the Sambucus Nigra L. extracts, including the description of the most important extraction methods for plant samples and of the encapsulation techniques and wall materials used to encapsulate polyphenols. It was also made an approach to the release tests involved in the release phenomenon of the bioactive compounds from the natural resources, including its mechanisms, simulated release media and kinetics.